The present application claims the priority of Japanese Patent Application No.2001-65665 filed on Mar. 8, 2001, which is incorporated herein.
The present invention relates to improvements in multiple optical path array type probes including a plurality of light guiding paths, multiple optical path array type optical heads employing the same, and particularly in refinements of distances between optical paths included in probes, and in methods for manufacturing the same.
It was generally the case with devices or equipments in which optical techniques are applied that limits in their performances were determined by wavelengths of light. For instance, it is impossible to observe any objects that are smaller than wavelengths of light by using a general optical microscope, and its resolution is limited.
Optical memories and similar were also known as recording materials for recording information applicable to computers or the like by using light. It was the case with such optical memories that upper limits of information recording densities were determined by diffraction limits of light and only marks of several hundreds of nm and thus approximating wavelengths of light could be recorded/read.
Novel techniques are being developed for such devices and equipments employing light in these years with which it is possible to get rid of restraints of wavelengths of light. There are techniques employing evanescent light or near-field light and are being paid attention to in view of their applicability to objects and regions that are smaller than wavelengths of light.
The following explanations will be made on the basis of an example of a microscope in which evanescent light or near-field light is applied. Known measuring theories are such in which a field of evanescent light or near-field light is generated on a sample surface into which a tip end portion of a probe is inserted for accordingly scattering the evanescent light or near-field light and thus measuring the scattered light, or such in which a field of evanescent light or near-field light is generated at the tip end portion of the probe whereupon the evanescent light or near-field light of the tip end portion of the probe is hit against the sample surface for scattering the evanescent light or near-field light and accordingly measuring the scattered light.
However, conventionally used probes were arranged in that a single light guiding path was formed in a single probe so that only one tip end portion to be inserted into a field of evanescent light or near-field light or only one tip end portion for generating such evanescent light or near-field light was present as well. Thus, it was time-consuming and energy-taking for observing surface information within a specified range of an object to be measured or an image on its a surface by using such a microscope with which such a region smaller than wavelengths of light could be observed.
While it is possible to perform optical analysis at high space resolution when using evanescent light or near-field light, excitation regions and measuring regions were partly overlapping in conventional probes so that it was required in evaluation of semiconductors to selectively measure emission of light right next to the excitation region which, however, could not be realized.
In the field of optical memories, near-field optical recording techniques are being paid attention to as compact recording devices capable of recording a large volume of information without being restrained by wavelengths of light for further improving recording densities. According to the near-field optical recording techniques, it is possible to perform recording/reading of an even larger volume of information by using media of identical size as those of conventional optical memories which is affected by improvements in recording densities.
An arrangement of an optical head used in such optical memories in which a plurality of near-field probes is aligned in a planar manner is being actively studied. Manufacturing costs caused a burden since a method was employed in which multi-staged film-forming/etching processes were performed with respect to Si wafers for manufacturing such probes.
Also, the accuracy of processing directly determined intervals between members corresponding to tip end portions of the probes. Thus, limits in correctness of shapes or intervals between tip end portions were determined through accuracy of processing so that intervals between tip end portions of probes of conventional optical heads fell in the range of approximately 30 xcexcm and the intervals were thus too large in view of recording densities. However, it is extremely difficult to manufacture the intervals between members corresponding to tip end portions of probes by orders of several xcexcm, and developments in novel manufacturing techniques were being desired. It was further impossible to apply improved techniques related to throughputs as cultivated in conventional techniques in the field of optical fibers when employing techniques for performing such processing.
Shapes of tip end portions of probes that could be manufactured were also limited.
The present invention has been made in view of the above subjects, and it is an object thereof to provide a probe that may correspond to various styles of measurement when used in microscopes and that is also applicable to recording devices, an optical head using the same, and a method for manufacturing such a probe in a simple and costless manner.
For achieving such objects, the method for manufacturing a multiple optical path array type probe according to the present invention is arranged in that in a light guiding material including a substrate that functions as a clad and a light guiding path formed of a component that functions as a core for guiding light or as a waveguide, the light guiding material includes a plurality of light guiding paths aligned to be parallel to each other within the substrate that functions as a clad, and tip end portions of the light guiding paths are sharpened through chemical etching of an end surface that is orthogonal to the plurality of light guiding paths.
In the method for manufacturing a multiple optical path array type probe of the present invention, the substrate that functions as the clad of the light guiding material consists of pure SiO2 and the light guiding paths of the light guiding material of a material in which SiO2 includes components such as metal or metal oxides, and chemical etching is performed by impregnating an end surface of the light guiding material into a HFxe2x80x94NH4 type buffer solution for a specified period of time.
It is preferable to manufacture the multiple optical path array type probe according to the present invention by using the above method for manufacturing a multiple optical path array type probe.
The multiple optical path array type probe according to the present invention is arranged in that in a light guiding material including a substrate of pure SiO2 that functions as a clad and a light guiding path of SiO2 including components such as metal or metal oxides formed of a component that functions as a core of a material for guiding light or as a waveguide, the light guiding material includes a plurality of light guiding paths aligned to be parallel to each other within the substrate that functions as a clad, and tip end portions of the light guiding paths are sharpened.
The multiple optical path array type probe according to the present invention is arranged in that in a light guiding material including a substrate that functions as a clad and a light guiding path formed of a component that functions as a core for guiding light or as a waveguide, the light guiding material includes a plurality of light guiding paths aligned to be parallel to each other within the substrate that functions as a clad, tip end portions of the light guiding paths are sharpened, and the respective light guiding paths are arranged in that an interval between mutually adjoining light guiding paths is not more than 20 xcexcm.
In the multiple optical path array type probe according to the present invention, it is preferable that the light guiding material is arranged in that a light transmittance preventing means is provided between the respective optical paths so that light is prevented from being transmitted between the respective optical paths.
In the multiple optical path array type probe according to the present invention, it is preferable that the light transmittance preventing means is a thin film layer made of gold.
In the multiple optical path array type probe according to the present invention, it is preferable that a plurality of light guiding paths are arranged in a linear form on an end surface that is orthogonal to the plurality of light guiding paths of the light guiding material.
In the multiple optical path array type probe according to the present invention, it is preferable that a plurality of light guiding paths are arranged in a latticed form on an end surface that is orthogonal to the plurality of light guiding paths of the light guiding material.
In the multiple optical path array type probe according to the present invention, it is preferable that the probe of multiple optical path is any one of a AFM probe, STM probe or a near-field probe.
In the multiple optical path array type probe according to the present invention, it is preferable that a mask of a light blocking material exhibiting ductility is formed at tip end portion of the sharpened light guiding paths, and wherein the probe further comprises holding materials for adjusting an amount of pressing, when forming an aperture of a specified size on all of the plurality of light guiding paths upon pressing the mask against a planar surface, to be of an aperture diameter that is formed upon pressing the same against the planar surface.
The multiple optical path array type optical head according to the present invention is arranged to be an optical head for recording/reading information for a near-filed optical memory by using the above multiple optical path array type probe.
In the multiple optical path array type optical head according to the present invention, it is preferable that the probe preferably comprises distance holding materials for securing a distance between a tip end of the probe and a surface of a recording material for recording/reading information.
The multiple optical path array type fiber according to the present invention is arranged in that in a light guiding material including a substrate that functions as a clad elongated in a linear manner and a light guiding path formed of a component that functions as a core for guiding light into the linear substrate or as a waveguide and extending in an extending direction of the substrate, the light guiding material includes a plurality of light guiding paths aligned to be parallel to each other within the substrate that functions as a clad.